The blotch is the skin tissue on which melanism takes place. Various methods of eliminating the blotch have heretofore been known, including a method of chemically peeling the blotch area on which hydrogen peroxide is applied and a method of vaporization of the blotch area by being irradiated with laser light.
However, it is very difficult to completely eliminate the blotch by these methods. Although a method of eliminating the blotch by irradiating it with laser light has attracted attention owing to its future, a high power laser light L is required, which is impinged upon the surface of the tissue M since a high proportion of the impinged laser light will be scattered in a rearward direction. A high proportion of the laser light which has been penetrated into the tissue will be scattered therein, resulting in that there is a risk that the unwanted tissue other than the target tissue might be damaged. Since the distribution of the strength of the laser light is such that the laser light induces higher temperatures in a core of an optical fiber and lower temperatures in the periphery thereof, uniform vaporization of the tissue can not be achieved. Since identification of the laser light irradiation position depends only upon visual monitoring, failure of irradiation of some of the target area is liable to occur.
It is therefore an object of the present invention to uniformly and efficiently irradiate the entire of a target tissue with laser light.